Steam-engine.



J. STUMPP.

STEAM ENGINE.

APPLICATION FILED AUG. 4, 1909.

Patented 00t.22,1912.

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JOHANN STUMPF, OF BERLIN, GERMANY.

STEAM-ENGINE.

Specification of Letters latent.

Patented Get.

Application filed August 4, 1909. Serial No. 511,126.

To all whom it may concern:

Be it known that I, JOHANN SrUMrr, professor, a subject of the King ofPrussia, German Emperor, and resident of 33 Kurfurstendamm. Berlin,Germany, have invented certain new and useful Improvements Relating toSteam-Engines, of which the following is a specification.

This invention relates to improvements in what are known asuni-directional flow or una flow steam engines and is a furtherdevelopment of the invention described in my co-pending applicationSerial No. 427,767, filed April 18, 1908. In that application I havedescribed a form of hot inlet chest which acts as a heater or jacket atthe end of the cylinder and which is usually provided with annularextensions which are formed in one with the end heater or jacket. Thistype of heater I have found specially applicable to most cases where thesuperheat is fairly high. "With saturated steam or only slightlysuperheated steam the requirements are different in order to retain theinternal walls at the proper temperature conditions for etiicientworking.

The present invention like that described in my prior application isbased primarily on the fact that the best way to prevent heat losses bysurface condensation in the cylinder is to maintain the internal skintemperature of the cylinder as high or higher than the steam to which itis exposed; more accurately stated the internal skin temperature shouldbe as high or higher than the saturation temperature of the steam towhich it is exposed. It is clear that with such conditions there can beno loss of heat from the working steam to the cylinder. This result isobtained in my prior application by the combined action of an end heaterand the compression of dry steam while the interior of the cylinder iskept out of communication with the cold exhaust as much as possible.

A hot end chest I have found. is not advisable for saturated or onlyslightly superheated steam as it is sometimes inadequate to maintain theskin temperature high enough.

According to the present invention, I propose to provide in addition toithe'cnd chest a separate heater over the cylindrical part i of thecylinder and extending toward but.

The cover j, of the cylinder is formel series With the end heater butthis is not an essential. The separate heater may ver conveniently begraduated so that the heating effect decreases toward the exhaustbelt.

The exhaust belt acts as a comparatively cold jacket about the middle ofthe cylinder, and is spaced from the separate annular heater. There isthus a neutral Zone or belt formed and located between the separatejacket and the cold belt. The separate jacket is in the form of anannular chamber or chambers. the inner wall of which is common with thecylinder wall.

The invention is illustrated in one convenient form in the accompanyingdrawing, which is a section through tne cylinder of an engine accordingto the present inven tion.

According to the form illustrated, steam is admitted to the cylinder 4,through ports Z), controlled by a valve 0, which is in turn operated bya reciprocating rod (Z. The valve 0, is arranged in the steam chest Offlow and acts as a hot chest and in th f illustrated is provided with anannular tension g. To this hollow cover nular extension 5 steam issupplied through a pipe h. Arranged close to one another and extendingfrom the inlet end toward the exhaust there are a plurality of ri gshaped chambers j, j j These chambers are connected by pipes toestablish a SQIMS. The annular extension 7, of the hollow cover f, isconnected by a pipe 7a, to the ring shaped chamber 7", and this pipeprovided with a valve m. The inner wtls of the annular or ring shapedchambers are common with the cylinder wall. In the form illustrated. thepipe 76, is arranged at the top side of the cylinder and the valve m, isconveniently in the form of an automatic reducing valve so that onlysteam of a predetermined pressure passes from the annular extension 9,to the first chamber 7", of the series. A pipe 7?. is arranged toconnect the lower or bottom side of the ring shaped chamber j, with thenextchamber y' in the series. he pipe if, is provided with a valve mwhich may conveniently be a reducing valve; The upper or top side of thering chamber j is connected by a pipe with a third chamber y' in theseries. The pipe A f, is provided with a valve m similar to the valvesm, and m From the bottom of the ring-shaped chamber 9' an last remaininsteam to be efi'ectively extracted. lt will be overflow or exhaust pipe70*, provided. which leads any steam or Water of condense,- tion awayfrom the ring-shaped chamber j.

For a short distance the cylinder at, is free of all jacketing up tillthe annular enhaust chamber a. The piston 0, in its strolre is adaptedto cover and uncover the ports 79, Which open into the-annular exhaustchamber a.

It till he understood that the arrangement describe'dis duplicated ateach end of the cylinder,- as can be seen from the drawing, whichillustrates a double-acting engine.

With the engine hereinbefore described it Will be seen that by suitablycontrolling the valves m, m m the pressure and temperature of the steamin the various ringshaped chambers may be accurately con trolled. Thetemperature to which the said rings heat the walls of the cylinder may,if desired, be slightly higher than the steam in the cylinder at thecorresponding parts of its expansion. The unheated part, of the cylinderbetween the ring-shaped chamber jiand the annular exhaust chamber at,which exercises a cooling action allow the quantities of heat in theseen that with a hot chest at the inlet end, a jaclreting over a part ofthe cylindrical Walls, bare part of the cylinder, and an exhaust casing,the cycle of operations on the cylinder Wall is (a) heating externallynear andifor a distance" from the inlet end. (16) no heating on theapproach to the exhaust and (c) coolingin the exhaust belt.

A further feature of the present invention is that the hollow cover f,is provided aoaaoei With a separate steam supply pipe it, as opposedtothe form of engine described in the prior application Serial No.427767, in which the hollow cover f, formed the Working steam chest. Byproviding aseparate steam supply the temperature of the worlc ing steam,preferably moderately superheated steam, is not lowered before it entersthe cylinder.

I claim:

1. In combination With a steam engine having an inlet port at its endand separate exhaust ports remote therefrom, a hot steam inlet chest atthe end of the cylinder, :1. separate annular heater about the cylinderextending from the inlet end toward the exhaust, and receiving steamfrom said chest, a steam connection from said chest to said heater,means for controlling the fiOW Of fluid in said connection, and anelongated piston working in said cylinder and controlling said exhaustports.

:2. The combination with a steam engine having an inlet port at its endand separate exhaust ports remote therefrom, a hot steam inlet chest atthe end of the cylinder, a separate annular heater composed of aplurality of annular chambers about the cylinder, connections unitingsaid chest and chambers in series, and means in each connection forcontrolling the flow of fluid through the same.

In Witness whereof I have hereunto set my hand in the presence of twoWitnesses.

J'OHANN srUMPr.

